100 Things #80: View Data in Real Time With the Multi-FFT and Multi-RTA

SoundCheck’s powerful virtual instruments let you perform measurements in real time, now with even more multichannel features in SoundCheck 21. Our new Multi-FFT allows for multiple FFT spectra on a single instrument, displayed in real time. The Multi-RTA virtual instrument enables multiple channels of measurement, also in real time. Both instruments can have independent per-channel configuration, perform real time calculations like power averaging, all can all be displayed on a single instrument. Of course, these instruments can be included within a sequence, so you can take advantage of the power measurements with SoundCheck sequence automation.

View Data in Real Time With the Multi-FFT and Multi-RTA

Learn more about the Multi-FFT, Multi-RTA, and more

SoundCheck features a full array of powerful virtual instruments, including the new Multi-FFT and Multi-RTA. Check out SoundCheck’s full features and functionality to learn more.

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Did you know that SoundCheck is the first Audio measurement system to offer multi-channel Real Time N-th Octave and FFT Spectrum analyzers that not only displays multiple signals simultaneously, but can also perform basic mathematical operations such as curve subtraction and power averaging in real time?

Both the Multi-RTA and Multi FFT instruments  support any number of channels, limited only by the physical test interface you are using with SoundCheck, and each channel can be configured independently. 

The Multi RTA allows you to analyze a signal using Constant-Percentage Bandwidth filters from Octave to 1/24th of an octave resolution. This is typically used for analyzing non-stationary signals such as speech and music on audio devices (such as smart devices). It can also be used for measuring active noise reduction with pink noise.

The Multi FFT uses  high resolution constant bandwidth filters that enables any number of live FFT spectra to be simultaneously viewed in real time. This resolution is helpful for viewing narrow frequency components such as pure tones and harmonics.

Both instruments offer real time calculations such as channel subtraction, maximum, minimum, average  and power calculations. These are displayed in the instrument in real time. This is useful, for example, for spatial averaging the sound pressure level  of a 6 mic array in automotive cabin measurements, or quickly checking headphone or earbud fit and seal before performing a measurement.

Another thing that’s really slick about this is that the FFT and RTA can be viewed simultaneously, either side by side or superimposed on one another in a single multi instrument. This enables both high resolution spectra and constant percentage bandwidth resolution (e.g. 1/12th Octave) measurements to be viewed at the same time. 

This could be used for analyzing broadband speech signals while accurately identifying single frequency interference tones, or analyzing intermodulation distortion in the presence of speech or music.

Another thing that you can do is drag and drop curves from the multi-channel instruments into another graph, or drag a static curve from another graph into the FFT or RTA to use as a reference. This has many applications such as comparison to a headphone target curve or automotive tuning applications.

We first introduced the Multichannel RTA in SoundCheck 19, added some extra functionality in SoundCheck 20, and introduced the multichannel FFT in SoundCheck 21. So if you’re using an older version of SoundCheck and want to check out this new functionality, contact your sales engineer or local rep to discuss an upgrade.